The present invention relates to the parenteral administration of nutriments to individuals, and more particularly, it relates to novel methods for the intravenous administration of hyperalimentary solutions to individuals who are unable to ingest sufficient materials to sustain themselves because of medical complications.
In the practice of medicine, patients are encountered who are malnourished and who cannot ingest any food orally, or who are unable to ingest sufficient quantities of food to sustain themselves. Such a condition is especially found in patients who have diseases of the alimentary system which, for example, interfere with the stomach or intestines. Similarly, difficulties in fulfilling the nutritional requirements of patients undergoing procedures such as esophageal resection are frequently encountered.
Attempts have been made to restore such patients nutritionally by intravenous hyperalimentation. Such intravenous hyperalimentation employs aqueous intravenous fluids having high concentrations of glucose and amino acids, fat and/or minerals which are injected into the peripheral vascular system. High concentrations of the nutrients are required in order to avoid the need for infusion of excessive quantities of fluids. Unfortunately, the high concentrations required are hyperosmolar and accordingly cause injury to the vessel wall and necessitate the placement of a catheter into a large systemic vein, such as the subclavian, or into the superior vena cava. Naturally, this puts a considerable load on the vascular system, because nutrients are normally absorbed from the intestinal tract and pass through the body organs so that there is no circulation of hyperosmolar glucose and amino acids. It has been found with intravenous hyperalimentation conducted conventionally that osmolar dehydration and hyperosmotic coma can occur. In some cases, metabolic acidosis occurs, and this can be a fatal complication. Further, rebound hyperinsulinemia can be a life-threatening event, so that prevention of these complications requires continued aggressive surveillance of the blood and urine glucose levels.
Other problems also occur in intravenous hyperalimentation. These arise from alterations in the peripheral blood amino acid concentration and composition. Thus, the amino acids can reach the cerebral circulation and cause alteration of the cerebral function. For instance, tryptophane, an essential amino acid, is required to be infused, but if it reaches the brain in high concentrations, it alters the serotonin concentration in the brain cells because tryptophane is a precursor of serotonin. Similarly, phenylalanine, another essential amino acid, causes excessive synthesis of norepinephrine and other catecholamines in the cerebral cells. The consequence of this systemic injection of amino acids can include such serious symptoms as muscle twitching and coma.
During fetal development, the umbilical vein returns blood from the placenta to the fetus. It was commonly assumed that, after division of the umbilical cord at birth, the lumen of the umbilical vein became obliterated and the vein wall then fibrosed. A cord-like remnant then persisted as the ligamentum teres hepatis in the free edge of the falciform ligament. In 1959, Gonzalez-Carbalhaes, Rev. Sanid, Milit. 12, 42 (1959), demonstrated that this "obliterated" vein could, in fact, be reopened to provide direct entry into the left portal vein. Since then, the reopened umbilical vein has been used for portography and chemotherapeutic purposes, as in the treatment of metastatic hepatic carcinomas. Various clinical and research uses of the reopened adult umbilical vein are described by Piccone, Bonanno, and LeVeen in Surgery, 63 (1), 29 (Jan. 1968).